Engines are generally known and widely used. Small engines, such as those used in lawn mowers, outboard marine operation, lawn equipment, generators, power washers, snow blowers, and so on, are also known and require lubrication, such as with oil. Small engines typically utilize an oil reservoir that gathers in the oil sump of the crankcase (i.e., the lower portion of the crankcase). It is known that engines, based on their orientation of the crankshaft, can be considered vertical crankshaft engines and horizontal crankshaft engines. Additionally, it is known to drive various components of the internal combustion utilizing a drivetrain that is driven (directly or indirectly) by the rotation of the crankshaft. It also known to utilize balance shafts to counteract forces and other vibrations in the engine that are not inherently balanced.
One problem experienced in certain engines that utilize an oil sump in which moving components are located in or near the oil sump is that the moving components can cause over-aeration of the oil reservoir in the oil sump, thereby causing unacceptable oil pressure drops in the forced oil flow circuit of the engine. The present invention addresses this, and other problems, of internal combustion engines.